Synthesis of Cycloalkanes from Lignocellulosic Platform

Abstract

Catalytic hydrodeoxygenation of biooil is instrumental in producing sustainable aviation fuels, specifically cycloalkanes, from lignocellulosic materials. Cycloalkanes typically have higher energy densities, lower freeze points and higher flash points than conventional jet fuel. In our study, we compared hydrodeoxygenation of p-cresol using Pd/C and tandem hydrogenation-dehydration using Pd/C for hydrogenation and heteropolyacid on alumina catalyst for dehydration. All of the hydrodeoxygenation and hydrogenation trials were ran at 250°C and 600 psi of hydrogen gas while dehydration to cycloalkenes were conducted at 250°C and 50 psi of argon gas. Hydrodeoxygenation produced less than 20% mol of cyclic hydrocarbons while tandem hydrogenation-dehydration presented an overall yield nearing to 60% mol. Results from the gas chromatography-mass spectroscopy analysis suggested isomerization of cyclohexene to metylcyclopentene occurred in runs utilizing heteropolyacid on alumina catalyst.